Thrombosis and Bleeding

Transcription

1 Many questions, few answers Thrombosis and Bleeding Pierre Noel MD Mayo Arizona

2 Scope of the Problem Thrombosis PV 12-39% ET 11-25% MF 10% 60-70% of thrombosis are arterial Splanchnic and cerebral thrombosis are more common Bleeding PV <10% ET 10-15% MF 15-20%

3 Why do we clot excessively? Platelet number? Activated platelets Increased hemoglobin Increased leukocytes JAK2V617F allele burden Inflammation CRP, Pentraxin 3 Decreased protein S (platelet proteases) Abnormal lining of blood vessels (Endothelium) Decreased NO in ET

4 Why do we bleed excessively? Decreased platelet granules Abnormal aggregation of platelets Increased breakdown of Von Willebrand molecule by ADAMTS13 Related to platelet count

5 Tefferi. Hemostasis and Thrombosis.LWW Treatment Algorithm Risk Category ET PV Management Pregnancy Low-risk Platelets < 1 M <60 No thrombosis hist. Low risk Platelets> 1 M High-risk Age>60 History Thrombosis High-risk refractory or intolerant to HU Low-dose ASA Low-dose ASA if risto cofactor activity >30% Low-dose ASA Phlebotomy Ht<45 Low-dose ASA if risto cofactor activity >30% + phelbotomy Low-dose ASA + HU Low-dose ASA + phlebotomy +HU Low-dose ASA + IFNα (<65) or busulfan (>65) Low-dose ASA + phlebotomy + IFNα (<65) or busulfan (>65) Low-dose ASA + Phlebotomy if PV Low-dose ASA if risto cofactor activity >30% + phlebotomy if PV Low-dose ASA + phlebotomy if PV + IFN-alpha Low-dose ASA + phlebotomy if PV+ IFN-α

6 Aspirin THROMBOSIS BLEEDING

7 From: The Role of Aspirin in Cardiovascular Prevention: Title and subtitle BreakImplications of Aspirin Resistance J Am Coll Cardiol. 2008;51(19): doi: /j.jacc Aspirin works by irreversibly inhibiting cyclooxygenase-1 (COX-1) on platelets, thereby reducing the production of thromboxane A2. Figure Legend: Inhibition of Platelet Thromboxane A2 Pathways by Low-Dose Aspirin Figure illustration by Rob Flewell. Date of download: 2/6/2013 Copyright The American College of Cardiology. All rights reserved.

8 Primary prevention Antithrombotic Trialists Collaboration Aspirin for primary prevention Metaanalysis Healthy volunteers Rates of thrombosis= 5.4/1000 person-years Reduction in thrombotic events 0.51%/y aspirin vs 0.57%/y controls (p=0.0001) Increase in GI and extracranial bleeds 0.1%/y aspirin vs 0.07%/y controls (p=0.0001) Baigent et al. Lancet, 2009.

9 Primary prevention I don t tolerate ASA 81 mg very well, it gives me heartburn, can I take Plavix instead? MPNs are associated with excessive thromboxane production. ASA impacts thromboxane production. No published data comparing ASA and Plavix in primary prevention Take ASA with food, consider proton pump inhibitor. Cumulative incidence of recurrent GI ulcer bleeding at 1 year is 8.6% with Plavix and 7.9% with aspirin and omeprazole (Chan FK et al, NEJM, 2005)

10 Primary Prevention Can I take ASA 325 mg instead of a baby aspirin (81 mg)? Majority of MPN studies were performed at doses <100 mg Risk of bleeding is 3X increased >200 mg/day

11 Primary Prevention I have an aspirin allergy, should I take Plavix? Role of Plavix in MPN primary prevention has not been studied. Not unreasonable. I have ET and am quite concerned about my risk of getting a stroke, can I use ASA 81 mg/day + Plavix 75 mg/day? No data for primary prevention Data from ISCALP study is not out (study closed) Risk of bleeding is at least 2X increased

12 Secondary prevention I had a recent TIA which lead to my diagnosis of ET. Should I receive ASA + Plavix? No specific data for MPN patients In non MPN patients the combination of ASA 81mg/ day + extended release dipyridamole 200 mg twice appears to be superior to ASA 81 mg alone. Indications of combined ASA + Plavix Acute coronary syndrome Drug eluting stent Bare metal stent

13 Aspirin resistance True resistance is rare! Compliance (50%) Competition for COX-1 binding site from ibuprofen and naproxen Increased platelet turnover (diabetes, cardiac surgery) Obesity (leptins increase platelet reactivity) Aspirin enteric coating Impaired sensitivity to COX-1 COX-1 polymorphisms Stimulation of platelets by ASA insensitive mechanisms

14 Secondary Prevention I had a TIA while taking ASA and Hydroxyurea, should I add Plavix? Commonly done (viewed by many as standard of care) Evidence of benefit in PV and ET is not proven Increases risk of bleeding (specially in patients >70 y) Role of ASA 325 mg once a day or 81 mg twice a day is unclear. I am a 47 yo male with ET, taking ASA 81 mg/d, I had a TIA last week, what should I do? Consider initiating cytoreductive therapy Consider adding Plavix

15 Secondary Prevention Seventy year old patient with PV, treated with phlebotomies + ASA + hydroxyurea develops a deep venous thrombosis or atrial fibrillation (AF). What is the best treatment? Best treatment for AF is anticoagulation with warfarin or dabigatran (Pradaxa ) or rivaroxaban (Xarelto ) Best treatment for DVT is anticoagulation with either warfarin or rivaroxaban (Xarelto ). Warfarin, rivaroxaban, dabigatran may not provide optimal prophylaxis for arterial thrombotic events (?), ASA may need to be added

16 Combination Therapy United Kingdom General practice Research database- 70,760 patients with Atrial Fibrillation. Risk of bleeding Warfarin RR 2.08 Clopidrogrel RR 1.57 Aspirin RR 1.25 Warfarin +ASA RR 2.87 Warfarin + clopidogrel RR 2.74 ASA + Clopidogrel RR 1.68 Triple Therapy RR 3.75 Azoulay et al. Thromb Haemost, 2013.

17 Hormone replacement and oral contraceptives I am a 34 yo woman with ET. I am on ASA 81 mg/ day. Can I take an oral contraceptive? Retrospective study demonstrated an increased risk of venous thrombosis (Gangat et a. Cancer, 2006) I am a 52 yo woman with ET. I would like to be on hormone replacement therapy. Is there any data? Retrospective data did not demonstrate increased risk of thrombosis (Gangat et a. Cancer, 2006)

18 Hormone replacement and oral contraceptives I am a 32 yo woman with PV, would like to be on an oral contraceptive. Advice PV is a risk factor for thrombosis Oral contraceptives : risk factor for thrombosis Level of protection provided by ASA? Prior history of thrombosis? Family history of thrombosis? Thrombophilia?

19 Bleeding 43 year old man with ET. No history of prior thrombosis. Platelet count of 1.35 million. Treated with ASA 81 mg/day. Presents with recurrent nosebleeds. Platelet aggregation study is abnormal ASA + ET Von Willebrand activity is decreased to 25% Recommend: D/C aspirin Arbitrary threshold to start HU is 1.5 M

20 Bleeding 43 year old man with ET. No history of prior thrombosis. Platelet count of 1.35 million. Treated with ASA 81 mg/day. Presents with recurrent nosebleeds. Patient develops left quadrant pain and requires surgery for diverticulitis. Options: 1- Pheresis < 800, Desmopressin 0.3 mcg/kg IV(VW short ½ life) 3- Cryoprecipitate or antihemophilic factor/von Willebrand complex (Alphanate, Humate-P )

21 Bleeding 78 yo man with history of coronary artery disease and PV, requires a total hip arthroplasty. His hematocrit is 51, his WBC is 12,000 and his platelet count is 1.1 million. He is on ASA 81 mg/day and takes HU intermittently. Pre-op recommendations: Hematocrit <45 Platelet count < 400,000 Post-op recommendations: Low-molecular heparin for 35 days Hold aspirin Hydroxyurea +/- phlebotomies (Ht <45)

22 Bleeding 67 year old woman with history of coronary heart disease and myelofibrosis, develops painful splenomegaly following portal vein thrombosis. Following splenectomy her platelet count rises > 1.4 M she develops a severe gastrointestinal bleed. 20% develop thrombocytosis post-splenectomy Mortality 20% (2/3 thrombosis, 1/3 GI bleeding) Options: Red cell transfusions Platelet pheresis Desmopressin (increased thrombotic risk) VW complex or cryoprecipitate

23 Thank you!